ia_vdw_m – BROWNPAK

Routines to evaulate pairwise potentials and their derivative.

The following styles are available:

Style 1. 12-6 LJ. See vdw_lj_set.
Style 2. Gaussian. See vdw_gaussian_set.
Style 3. Cosine. See vdw_cosine_set.
Style 4. Screened Coulomb + LJ. See vdw_lj_coul_debye_set.
Style 5. Coulomb + LJ. See vdw_lj_coul_set.
Style 6. Standard DPD. See vdw_dpd_set.

Uses

- constants_m
- atmcfg_m
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Used by

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Nodes of different colours represent the following:

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Subroutines

ia_vdw_setup ia_get_vdw_force vdw_lj_set vdw_lj vdw_gaussian_set vdw_gaussian vdw_cosine_set vdw_cosine vdw_lj_coul_debye_set vdw_lj_coul_debye vdw_lj_coul_set vdw_lj_coul vdw_dpd_set vdw_dpd

Subroutines

public subroutine ia_vdw_setup(num_vdw_types, vdw_styles, vdw_params)

Sets up parameters for vdw potentials

Arguments

Type	Intent	Attributes		Name
integer,	intent(in)		::	num_vdw_types	Number of types of vdw interactions
integer,	intent(in),	dimension(:)	::	vdw_styles	Styles for each type
real(kind=rp),	intent(inout),	dimension(:,:)	::	vdw_params	Parameters for each type, depending on style

public subroutine ia_get_vdw_force(rij_mag, qi, qj, sty, params, enrg, frc, ierr)

Calculates the energy & its derivative due to a single interacting pair of atoms.

Arguments

Type	Intent	Attributes		Name
real(kind=rp),	intent(in)		::	rij_mag	Distance between two atoms
real(kind=rp),	intent(in)		::	qi	Charge on atom i
real(kind=rp),	intent(in)		::	qj	Charge on atom j
integer,	intent(in)		::	sty	Style of vdw interaction
real(kind=rp),	intent(in),	dimension(:)	::	params	Parameters for vdw interaction
real(kind=rp),	intent(out)		::	enrg	Energy
real(kind=rp),	intent(out)		::	frc	Derivative of the potential. This is the magnitude of force due to this potential.
integer,	intent(out)		::	ierr	Error flag

private subroutine vdw_lj_set(params, eps, sigma, rcut)

Setter for 12-6 LJ (truncated & force-shifted) interaction.

Arguments

Type	Intent	Optional	Attributes		Name
real(kind=rp),	intent(inout),		dimension(:)	::	params
real(kind=rp),	intent(in),	optional		::	eps
real(kind=rp),	intent(in),	optional		::	sigma
real(kind=rp),	intent(in),	optional		::	rcut

private pure subroutine vdw_lj(r, params, enrg, frc)

Evaluates the potential and its derivative for LJ interaction. See vdw_lj_set.

Arguments

Type	Intent	Attributes		Name
real(kind=rp),	intent(in)		::	r
real(kind=rp),	intent(in),	dimension(:)	::	params
real(kind=rp),	intent(out)		::	enrg
real(kind=rp),	intent(out)		::	frc

private subroutine vdw_gaussian_set(params, A, B, rcut)

Setter for gaussian interaction. The potential is truncated and force-shifted.

Arguments

Type	Intent	Optional	Attributes		Name
real(kind=rp),	intent(inout),		dimension(:)	::	params
real(kind=rp),	intent(in),	optional		::	A
real(kind=rp),	intent(in),	optional		::	B
real(kind=rp),	intent(in),	optional		::	rcut

private pure subroutine vdw_gaussian(r, params, enrg, frc)

Calculates energy & its derivative for gaussian interaction. See vdw_gaussian_set.

Arguments

Type	Intent	Attributes		Name
real(kind=rp),	intent(in)		::	r
real(kind=rp),	intent(in),	dimension(:)	::	params
real(kind=rp),	intent(out)		::	enrg
real(kind=rp),	intent(out)		::	frc

private subroutine vdw_cosine_set(params, A, rcut)

Setter for cosine interaction.

Arguments

Type	Intent	Optional	Attributes		Name
real(kind=rp),	intent(inout),		dimension(:)	::	params
real(kind=rp),	intent(in),	optional		::	A
real(kind=rp),	intent(in),	optional		::	rcut

private pure subroutine vdw_cosine(r, params, enrg, frc)

Evaluates the potential and its derivative for cosine interaction. See vdw_cosine_set.

Arguments

Type	Intent	Attributes		Name
real(kind=rp),	intent(in)		::	r
real(kind=rp),	intent(in),	dimension(:)	::	params
real(kind=rp),	intent(out)		::	enrg
real(kind=rp),	intent(out)		::	frc

private subroutine vdw_lj_coul_debye_set(params, eps, sigma, rcut, rcut_coul, C, kappa)

Setter for 12-6 LJ with screened Coulombic interaction.

Arguments

Type	Intent	Optional	Attributes		Name
real(kind=rp),	intent(inout),		dimension(:)	::	params
real(kind=rp),	intent(in),	optional		::	eps
real(kind=rp),	intent(in),	optional		::	sigma
real(kind=rp),	intent(in),	optional		::	rcut
real(kind=rp),	intent(in),	optional		::	rcut_coul
real(kind=rp),	intent(in),	optional		::	C
real(kind=rp),	intent(in),	optional		::	kappa

private pure subroutine vdw_lj_coul_debye(r, qiqj, params, enrg, frc)

Evaluates the potential and its derivative for screened Coulombic interaction combined with 12-6 LJ (cut & shifted). See vdw_lj_coul_debye_set.

Arguments

Type	Intent	Attributes		Name
real(kind=rp),	intent(in)		::	r
real(kind=rp),	intent(in)		::	qiqj
real(kind=rp),	intent(in),	dimension(:)	::	params
real(kind=rp),	intent(out)		::	enrg
real(kind=rp),	intent(out)		::	frc

private subroutine vdw_lj_coul_set(params, eps, sigma, rcut, rcut_coul, C)

Setter for 12-6 LJ with Coulombic interaction.

Arguments

Type	Intent	Optional	Attributes		Name
real(kind=rp),	intent(inout),		dimension(:)	::	params
real(kind=rp),	intent(in),	optional		::	eps
real(kind=rp),	intent(in),	optional		::	sigma
real(kind=rp),	intent(in),	optional		::	rcut
real(kind=rp),	intent(in),	optional		::	rcut_coul
real(kind=rp),	intent(in),	optional		::	C

private pure subroutine vdw_lj_coul(r, qiqj, params, enrg, frc)

Evaluates the potential and its derivative for Coulombic interaction combined with 12-6 LJ (cut & shifted). See vdw_lj_coul_set.

Arguments

Type	Intent	Attributes		Name
real(kind=rp),	intent(in)		::	r
real(kind=rp),	intent(in)		::	qiqj
real(kind=rp),	intent(in),	dimension(:)	::	params
real(kind=rp),	intent(out)		::	enrg
real(kind=rp),	intent(out)		::	frc

private subroutine vdw_dpd_set(params, A, rcut)

Setter for standard DPD interaction.

Arguments

Type	Intent	Optional	Attributes		Name
real(kind=rp),	intent(inout),		dimension(:)	::	params
real(kind=rp),	intent(in),	optional		::	A
real(kind=rp),	intent(in),	optional		::	rcut

private pure subroutine vdw_dpd(r, params, enrg, frc)

Evaluates the potential and its derivative for standard DPD interaction. See vdw_dpd_set.

Arguments

Type	Intent	Attributes		Name
real(kind=rp),	intent(in)		::	r
real(kind=rp),	intent(in),	dimension(:)	::	params
real(kind=rp),	intent(out)		::	enrg
real(kind=rp),	intent(out)		::	frc

ia_vdw_m Module

Contents

Subroutines

Uses

Used by

Contents

Subroutines

Subroutines

public subroutine ia_vdw_setup(num_vdw_types, vdw_styles, vdw_params)

Arguments

public subroutine ia_get_vdw_force(rij_mag, qi, qj, sty, params, enrg, frc, ierr)

Arguments

private subroutine vdw_lj_set(params, eps, sigma, rcut)

Arguments

private pure subroutine vdw_lj(r, params, enrg, frc)

Arguments

private subroutine vdw_gaussian_set(params, A, B, rcut)

Arguments

private pure subroutine vdw_gaussian(r, params, enrg, frc)

Arguments

private subroutine vdw_cosine_set(params, A, rcut)

Arguments

private pure subroutine vdw_cosine(r, params, enrg, frc)

Arguments

private subroutine vdw_lj_coul_debye_set(params, eps, sigma, rcut, rcut_coul, C, kappa)

Arguments

private pure subroutine vdw_lj_coul_debye(r, qiqj, params, enrg, frc)

Arguments

private subroutine vdw_lj_coul_set(params, eps, sigma, rcut, rcut_coul, C)

Arguments

private pure subroutine vdw_lj_coul(r, qiqj, params, enrg, frc)

Arguments

private subroutine vdw_dpd_set(params, A, rcut)

Arguments

private pure subroutine vdw_dpd(r, params, enrg, frc)

Arguments